6-Methylchromone-2-carboxylic Acid → 6-methyl-3,4-dihydro-2H-1-benzopyran-2-carboxylic acid

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Reaction Steps

6-Methyl-4-oxo-4H-1-benzopyran-2-carboxylic acid (Niviere, et al., 1965) was hydrogenated over a palladium-on-carbon catalyst to give 3,4-dihydro-6-methyl-2H-1-benzopyran-2-carboxylic acid. This acid was converted to the acid chloride with thionyl chloride and the acid chloride was converted to 9, obtained as white plates, mp: 67°-67.5° C., by treatment with 2-propenamine, all by the procedures described in Example 1.

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